The present invention relates to a method and apparatus for extracting low SNR (signal to noise ratio) transient signals from noise. The invention is particularly useful in identifying and extracting low, evoked potential (EP) signals appearing in an electroencephalogram (EEG) of a living being generated in response to sensory stimulation of the nervous system of the living being. The invention is therefore described below with respect to this applications, but it will be appreciated that the invention could also be used in other applications.